Indoor noise in internal combustion engine vehicles, ships and aircrafts has been issued. To prevent indoor noise, various sound absorption materials have been produced and marketed.
Melt-blown fiber webs have excellent sound absorption performance and light unit weight, and thus have been used as sound absorption materials. Such fiber webs can be produced from thermoplastic resin by melt-blown technology.
Korean Patent Application No. 10-2010-7000497 discloses a porous nonwoven web comprising staple fibers intermingled with melt-blown fibers, wherein the melt-blown fibers comprise a bimodal mixture of intermingled microfibers and mesofibers, and wherein there are at least about five times as many microfibers as mesofibers and wherein the mesofibers comprise at least about 30% by weight of the melt-blown fibers.
In addition, Korean Patent No. 0903559 discloses a sound-absorbing nonwoven fabric, which comprises a specific amount of hollow conjugated staple fibers uniformly dispersed in a melt-blown nonwoven fabric made of bicomponent microfibers and has a large surface area per unit weight and good sound absorption performance.